The present invention is directed to a stitching device and a method for stitching printed products.
In the manufacture of printed products, such as books, there are many separate operations required to print, assemble and bind the final products. These operations often include a stitching operation to stitch loose, unbound books into finished, bound books. Typically, unbound books are transported at registered positions on chains of a saddle-back conveyor within a stitcher. The saddle-back conveyor transports the loose, unbound books past a stitching device that operates to stitch the unbound books into finished products. Examples of known stitching devices that utilize chains for transport of unbound, printed products, as just described, include the SP-1000 and ST-400 models manufactured by Heidelberger Druckinaschinen AG.
The use of chains for transferring unbound, printed products, however, generally involves a relatively high maintenance and costly operation. For example, the chains require lubrication, which involves not only the efforts of personnel to perform the steps needed to lubricate the chains, but also the time and effort to monitor the operation of the saddle-back conveyor to determine when lubrication is necessary. In addition, the use of chains results in high noise levels during operation of the stitcher. Moreover, it is difficult to maintain an even stretch tension in the chain for proper and efficient operation.
Thus, it would be advantageous to provide a stitcher having conveyor equipment that replaced the chains of a saddle-back conveyor so as to reduce the disadvantages associated with chain transports for unbound, printed products in a stitcher.